it's not necessarily a title.tik file that you need, could be "random_name.ext" with the key at 0x1bf and it will work too.
example to generate an empty file with the key at the correct position with python
Code:python -c "import binascii; open('title.tik', 'wb').write(b'\0'*0x1bf + binascii.unhexlify('<pasteyourkeyhereinbetweenthequotes>'.replace(' ','')))"
Say if I download a full game using nusgrabber, will the title key of that title work to decrypt the download?